feat: page navigation by privilege, testing login errors

[clovertera]

My implementation is that admin and user trying to access /login after they already logged in get redirected - I hope this is what was expected here.
/admin is still a rough work in progress for the moment, it will be improved

about /admin, I implemented the protectedroute component inside src/routes.tsx - it was commented out before so I'm unsure if I was supposed to change this or if there was a reason this was commented out

implemented the fix for printing the error message
can I refine the error messages in the auth controller login function or do they need to stay as they are?

[BoYanZh]

i think that's good, we can even just redirect admin to manage movie page. LGTM.